JP 2001-8363 A discloses a load driving device (i.e., a lamp lighting device) including a switching element (i.e., MOSFET), a timer and a controller. The switching element has a function of self-cutoff at an excess temperature and is turned on to provide electric power from a voltage source (i.e., a battery) to a load (i.e., a lamp). The timer operates from a time point at which an energization to the switching element is started. During an operation period of the timer, the controller conducts the switching element again when the temperature of the switching element increases to a constant value and the switching element is cutoff.